Attachment for grinding centers.



0. L. PETRIKIN.

PATENTED MAR. 5, 1907.

ATTACHMENT FOR GRINDING CENTERS.

APPLICATION FILED SEPT, 24. 1906.

2 SHEETS-SHEET 1.

I W/TNESSES INVENTOH Cyzzzrleo" HZI. JZrJ/Ze'n m go ATTORNEYS No. 846,245: PATENTED MAR. 5, 1907.

c. L. PETRIKIN. ATTACHMENT FOR GRINDING CENTERS.

APPLICATION FILED SEPT. 24. 1906.

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/NVENTOH A TTUBNEYS UNITED; STATES PATENT OFFICE.

CHARLES LLOYD PETRIKIN, OF 'MUNCY, PENNSYLVANIA.

ATTACHMENT FOR GRINDING-CENTERS.

I No. 846,245.

Specification of Letters Patent.

Patented March 5, 1907.

Application filed September 24,1906. Serial No- 335.902. I

To all whom it concern:

Be it known that'I, CHARLES LLOYD PET-- This invention is an lmproved centergrinder constructed in the form of an attachment especially designed to be applied to 'lathes and employed in grinding the centers contained therein. The invention contemplates the production of a device of this character of simple construction, driven from the lathe in a novel manner and acting whenoperated' to grind the center with accuracy and facility.'

One embodiment of the invention consists of a frame substantially U-shaped supported in a horizontal diagonal position from the tail-stock spindle when applied to the lathe, a convenient form of clamp being employed adapting the frame to bereadily attachedand detached. J ournaled in the extremities of the frame is a shaft, frictionally driven from the [lathe face-plate and itself acting to frictionally drive a second shaft, journaled parallel thereto in the frame, the second shaft carrying a grinding-wheel at its inner extremity and slidingly mounted in its bearings, whereby the grinding-wheel may be reciprocated over the lathe-center as both revolve in opposite directions.

Reference is to be had to the accompanying drawings,forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a plan of the preferred form of my invention as applied ,to a lathe, parts of the construction being shown in central horizontal section. Fig. 2 is a transverse vertical sectional view substantially on the line 2 2 of Fig. 1, and Fig. 3 is a sectional view on the line 3 3 of Fig. 1 looking in the direction of the arrow.

The ,invention comprises a frame 1, substantia lly U-shaped, supported in a horizon- 'tal diagonal position from the spindle of the inner face, as illustrated in Fig. 2. The 'aw 4 1s slldably mounted in a strap 5, curve at its lower end, and is operated by a screw 6,

swiveled to it and threaded through the upper end of the strap, and a reinforcing-block 7 attached thereto, the screw being provided at its upperextremity with any preferred form-of operating-handle 8..

The outer extremities of the frame 1 are provided withbearings 9 and 9", having journaled therein a sleeve 10 and a shaft 11, respectively. The shaft also passes through the sleeve 10 and is slidably securedthereto by a set-screw or key 12, the extremity of which slidably engages with a keyway 13 out into the shaft. At the inner end of the shaft 11 a beveled friction-wheel 14 is fixed, acting to frictionally engage a disk 15, secured by bolts or other suitable means to the faceplate of the lathe. Thisfriction-wheel is normally pressed into contact with the disk by a spring 16, contained between the inner face of the bearing 9 and a cup-shaped collar 17, adjustably secured to the shaft 11 by a set-screw 18. I

Secured to the outer end of the sleeve 10 is a large friction-wheel 19, the periphery of which is frictionally engaged by the frictional device consisting of a collar 20, fixed by 'aiset-screw 21 to a sleeve 22, and a collar 23, pressed inwardly against the opposite side of the friction-wheel 19 by a spring 24:, the collar being cup-shaped and shdable over a fixed collar 25 and the sleeve 22 and the spring 24 being contained therebetween. Slidably mounted in the sleeve 22 and within a bearing 26 at the opposite side of'the frame is a shaft 27, the shaft and sleeve being held from relative rotary movement by a setscrew 28, securing the collar 25 and sleeve together and thereafter projecting into a key way 29 cut into the shaft. Removably secured to the inner end of the shaft is a grinding-wheel 30, adapted to be projected back and forth across the lathe-center by a knob 31, j ournaled on the reduced opposite end of the shaft and held in place by the setscrew and washer shown.

It is obvious from the construction described that as the lathe-center revolves in one direction the grinding-wheel will be rapidly revolved in 'the opposite direction through the intermediate frictional mechanism and employed by the reciprocation of the shaft 27 to grind the center to the re uired a jaw 4 of a clamp, protruding slightly at its 1 angle with facility, it being understoo that the angle of the shaft 27 is the same asthat required for standard centers, which in practice is about sixty degrees. After the center of the head-stock spindle has been ground it may be interchanged with the dead-center of the tail-stock and that also ground in a similar manner. i

The extent to which the shaft 11, carrying the friction wheel 14, should project beyond the frame will depend on the diameter of the grinding-wheel 30, as is obvious, and is to be regulated by adjusting the collar 17 on the shaft 11.

Although I, have described the preferred form of the invention in detail in order that the construction and operation might be fully understood, I regard the precise embodiment as not material, provided the essential characteristics are employed as pointed out in the annexed claims.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. An attachment for grinding lathe-centers comprising a frame having means to rigidly clamp it to the tail-stock of the lathe, two shafts journaled in the frame, meansfor frictionally driving one of said shafts from the lathe, a grinding-wheel fixed to the other shaft and driven by the frictionally-driven shaft, and means for reciprocating the grinding-whcel.

2. An attachment for grinding lathe-centers comprising a substantially U-shaped frame, grinding means journaled in said frame, and means clamping the frame to the spindle of the tailestock of the lathe and supporting it therefrom in a horizontal, diagonal position. g 3. An attachment for grinding lathe-centers comprising a frame, shafts journale'd transversely in the frame, a friction-wheel fixed to one of said shafts, a collar fixed to the friction-wheel shaft between the frame, a spring interposed between the collar and frame, means for frictionally driving the other shaft from the friction-wheel shaft, a grinding wheel fixed to said other shaft, and means for reciprocating said shaft in its bearings whereby the grinding-wheel is moved back and forth over the lathe-center.

4. An attachment for grinding lathe-cen- 'ters, comprising a U-shaped frame, two shafts transversely journaled in the frame, a friction-wheel fixed to the outer end of one of said shafts, a grinding-wheel fixed to the outer end of the other shaft, a friction-wheel fixed to the friction-wheel shaft within the frame, a friction-collar ri idly carried by the grinding-wheel shaft an engaging one side of the friction wheel fixed within the frame, a second collar slidable. over the grindingwheel shaft ada ted to engage the opposite side of the friction-wheel within the frame, and a s ring interposed between said slidable col ar and the frame. v

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CHARLES LLOYD PETRIKIN.

Witnesses:

Roar. K. REEDER, H. R. CLARKE. 

